WO2014202520A1

WO2014202520A1 - Decontamination unit for a potentially pathogenic fluid and decontamination installation including such a unit

Info

Publication number: WO2014202520A1
Application number: PCT/EP2014/062543
Authority: WO
Inventors: Frédéric Laurent DE STOUTZ
Original assignee: Actini
Priority date: 2013-06-18
Filing date: 2014-06-16
Publication date: 2014-12-24
Also published as: EP3010858A1; FR3007021B1; EP3010858B1; CA2915774A1; CA2915774C; US20160145121A1; EP3010858B9; FR3007021A1

Abstract

The invention relates to a decontamination unit (19) for potentially pathogenic fluids including a treatment tank (29) and at least one heating element (31). The treatment tank (29) includes a flat bottom (33) and at least one heating element (31) fastened on the outer side (35) of the flat bottom (31) opposite the lower side (37) designed to come into contact with the potentially pathogenic fluid.

Description

Unit for decontaminating a potentially pathogenic fluid and decontamination facility comprising such a unit

The present invention relates to a unit for decontaminating a potentially pathogenic fluid and a decontamination installation comprising such a unit.

The invention is particularly applicable in the context of effluent treatment units potentially contaminated with germs or infectious agents such as viruses, bacteria, parasites (protozoa, helminths) or even prion-type proteins. In laboratories or hospitals, staff are often in contact (admittedly usually indirectly via gloves) with potentially pathogenic fluids following sampling or handling in the course of their work or have to handle objects, for example containers or specimens, which had been in contact with such a pathogenic fluid which requires washing underwater for example objects or parts of the body which had been in contact with the pathogenic fluid.

The water used for washing / cleaning is therefore potentially contaminated and can not be put in the sewer without prior decontamination.

For this purpose, in the majority of laboratories and hospitals, the water points and in particular the sinks are connected to an effluent circuit going to a central decontamination facility.

However, depending on the size of laboratories, hospitals or research centers and their specific activities, the quantities of water used are low and the investment in a central thermal decontamination treatment facility is too high, especially as it is necessary to provide for a building a specific circuit of potentially contaminated water in parallel with the standard wastewater circuit.

Other facilities that have multiple laboratories prefer not to centralize the collection of effluents for common treatment so as not to risk "breaking" the confinement of their room and give priority to on-site treatment.

To overcome this problem, it is known to provide a local and autonomous installation of small decontamination. However, the known installations are not satisfactory.

Indeed, document JPH03157185 discloses an installation comprising two decontamination units so that the contaminated water can be received in one unit while the other unit is heated during a decontamination cycle. However, this installation is quite expensive since it is necessary to provide two complete decontamination units with their heating elements, control and valves. In addition, this installation requires the use of a pump to circulate the potentially contaminated fluids which is a source of noise and may pose a safety problem in case of failure of the pump seal.

In addition, the heating element 9a or 9b of this document penetrates directly into the decontamination tank which has two disadvantages.

Indeed, the heating body is directly in contact with the contaminated fluid so that limestone can be deposited directly on the heating elements and then reduce the heat transfer, which results in a greater and unnecessary energy expenditure and a risk that the heating temperature necessary for effective decontamination (for example 135 C) is no longer reached. In addition, the maintenance of these heating elements is difficult because of the integrated assembly in the tank and the fact that they had been in contact with the potentially pathogenic fluids.

In addition, the applicant has noted a temperature gradient between the top and the bottom of the tank of the aforementioned document, which is also a risk since the decontamination conditions for the fluid at the bottom of the tank probably do not have been respected because of a temperature too low.

In order to at least partially overcome the previously mentioned defects, the object of the invention is an improved decontamination unit. To this end, the subject of the invention is a unit for decontaminating potentially pathogenic fluids comprising a treatment tank and at least one heating element, characterized in that the treatment tank comprises a flat bottom and at least one heating element fixed on the outer side of the plane bottom opposite the inner side intended to be in contact with the potentially pathogenic fluid, characterized in that the flat bottom of the treatment tank is inclined.

Thus, by fixing the heating elements directly against the bottom of the volume of the treatment tank, they are no longer in contact with the potentially pathogenic fluid. As a result, there is no longer formation of limestone or scale on the heating elements so that their effectiveness is not impaired over time. In addition, by the arrangement of the heating elements, it ensures a more homogeneous heating of the potentially pathogenic fluid and avoid dead zones.

Thanks to the inclined bottom, the limestone or tart that can form on the bottom will accumulate at the bottom of the slope and then be removed at the end of the decontamination cycle with the decontaminated fluid. Moreover, by this inclination of the bottom, during heating by the heating elements, is induced in the treatment tank a circular movement (from bottom to top) of the potentially pathogenic fluid which contributes to a very homogeneous heating of the fluid, which is important to ensure good decontamination of infectious agents in the fluid. Thus, one can ensure this homogeneous heating without additional electric motor, which is cheaper and also more reliable from a maintenance point of view.

The invention may further comprise one or more of the following characteristics taken alone or in combination: The bottom plan of the treatment tank may be inclined between

5% -10%, preferably 7%.

In another aspect, an outlet of the treatment tank is formed at the bottom inclined plane at the bottom of the slope.

The heating element is for example a circular flat resistor.

In another aspect, the unit comprises a plurality of at least two concentric flat resistors.

In another aspect, the treatment tank is made of stainless steel, preferably type 316L. The invention also relates to an installation of decontamination including

a sink for collecting potentially pathogenic fluids,

a storage vessel for the potentially pathogenic fluid collected fluidly connected to the sink, a decontamination unit as described above, the inlet of which is fluidly connected to the outlet of the storage tank, and

a heat exchanger whose inlet is fluidly connected to the outlet of the decontamination unit.

In one aspect, the sink is disposed above the storage tank, the storage tank is disposed above the decontamination unit, and the decontamination unit is disposed above the heat exchanger. so that the circulation of potentially pathogenic fluids in the installation is achieved by gravity. In another aspect, the installation comprises a first control valve disposed in a pipe connecting the storage tank to the decontamination unit and a second control valve disposed in a pipe connecting the decontamination unit to the heat exchanger. . The invention also relates to a process for decontaminating potentially pathogenic fluids in a decontamination unit as described above, characterized in that

the treatment tank is filled with a potentially pathogenic fluid while leaving a gaseous volume of expansion inside the treatment tank, the potentially pathogenic fluid is heated at a temperature of between 130 ° C. and 140 ° C., preferably at 135 ° C. for a period of between 1.5 min and 3 min, preferably for 2 min, allowing the pressure to be increased in the treatment tank ,

the fluid thus decontaminated is evacuated.

Other characteristics and advantages will appear on reading the description of the following figures, among which:

FIG. 1 is a block diagram of the decontamination installation according to one embodiment,

FIG. 2 is a schematic side view of an embodiment of the decontamination installation according to one embodiment,

FIG. 3 shows a detail of FIG. 2, in particular the decontamination unit according to one embodiment, FIG. 4 is a diagrammatic sectional view of one embodiment of the decontamination installation according to one embodiment. , and

FIG. 5 is a flowchart showing an example of different steps of a decontamination process.

In all the figures, the same elements bear the same reference numbers.

One embodiment of the present invention will be described below with reference to the various figures.

FIG. 1 shows a block diagram of a decontamination installation 1 according to one embodiment and FIG. 2 shows a schematic side view of an embodiment of the installation of decontamination 1.

Thus, the decontamination installation 1 comprises for example a town water tap 3 connected to an inlet 4 of city water for the pre-cleaning or washing of objects, for example test pieces. Preferably, the valve can be operated without contact, for example via an infrared sensor or a capacitive sensor. Above the outlet of the tap 3 is arranged a sink 5 for collecting potentially pathogenic fluids, that is to say specimen residues containing for example infectious agents. The sink 5 is for example made of type 304 stainless steel.

The outlet of the sink 5 is connected by an evacuation pipe 7 to the inlet of a storage tank 9 placed below the sink 5 so that the potentially pathogenic and contaminated fluids are evacuated by gravity into the tank 9. This storage tank 9 is for example made of stainless steel type

316L and can have a capacity of eg 251.

As can be seen in Figure 1, the storage tank 9 is equipped with a level sensor 11. The latter is connected to a control unit (control panel 13 visible in Figure 2) to probe the level in the storage tank 9, engage according to the level reaches a decontamination cycle and, where appropriate, block a stop valve 15 of tap water supplying the valve 3 to prevent an overflow of pathogenic fluid in the sink 5.

The outlet of the storage tank 9 is connected by a pipe 17 to a decontamination unit 19 which is arranged below the storage tank 9 so that the potentially pathogenic fluids are discharged by gravity into the storage unit. decontamination 19. A regulating valve 21 arranged in the pipe connecting the storage tank 9 to the decontamination unit 19 regulates the flow, for example for filling the decontamination tank 19 and is controlled by the unit of decontamination. control 13. The output of the decontamination unit 19 is connected via a pipe 22 to an inlet of a heat exchanger 23 for cooling the decontaminated fluid at the outlet of the decontamination unit 19. Another inlet of the exchanger thermal 23 is connected to the tap water. The heat exchanger 23 has two outlets, a decontaminated and cooled fluid outlet 24 and a town water outlet 26 having served as coolant in the heat exchanger 23. Thus the mains water network is always separated from the pipes of the decontaminated fluid so that there is no possibility of a return contamination, which further increases the safety of the installation described here.

As can be seen in FIG. 2, the elongate heat exchanger 23 for maximizing the exchange surfaces is disposed below the decontamination unit 19 so that the decontaminated fluid at the outlet of the decontamination unit 19 can also transit by gravity.

A control valve 25 (FIG. 1) disposed in the pipe 22 connecting the decontamination unit 19 to the heat exchanger 23 makes it possible to regulate the flow, for example to evacuate the decontamination tank 19 and is controlled by the control unit. control 13.

We will now describe in more detail the unity of decontamination 19 of potentially pathogenic fluids.

This decontamination unit 19 comprising a treatment tank 29, for example made of stainless steel, preferably type 316L, and at least one heating element 31, preferably several heating elements. The volume of the treatment tank is, for example, 121.

As can be seen in FIGS. 2 to 4, the treatment tank 29 comprises a flat bottom 33 or a flat bottom and two heating elements 31A and 31B (see FIGS. 3 and 4) which are flat, circular and concentric, for example 2, 3kW of power are fixed, for example with a cross bolted mechanical mount, on the outer side 35 of the bottom plane 33 opposite the inner side 37 intended to be in contact with the potentially pathogenic fluid.

Thus, by fixing the heating elements 31A and 31B directly against the bottom of the volume of the treatment tank 29, they are no longer in contact with the potentially pathogenic fluid. As a result, there is no longer formation of limestone or scale on the heating elements so that their effectiveness is not impaired over time. In addition, by the arrangement of the heating elements, it ensures a more homogeneous heating of the potentially pathogenic fluid and dead zones are avoided.

As can be seen in FIGS. 2 to 4, the planar bottom 33 of the treatment tank 29 is inclined, for example between 5% -10%, preferably 7% (that is to say at an angle of 4 ^° with respect to the horizontal). This has the consequence that the limestone or tart that can form on the bottom will accumulate at the bottom of the slope (see arrow 39) and then be evacuated at the end of the decontamination cycle with the decontaminated fluid.

In addition, by this inclination of the bottom, during heating by the heating elements 31A and 31B, is induced in the treatment tank 29 a circular movement (from bottom to top) of the potentially pathogenic fluid (see arrow 41 in Figure 2 ) which contributes to a very homogeneous heating of this fluid, which is important to ensure good decontamination of infectious agents in the fluid.

Furthermore, the outlet 43 of the treatment tank 29 is arranged at the bottom of the inclined plane 33, at the bottom of the slope, which also promotes the evacuation of residues or particles (for example pie or limestone) after a cycle. decontamination.

In addition, the top of the treatment tank 29 has the shape of a dome 45 to serve as an expansion vessel during heating. Thus, during heating, the pressure in the treatment tank 29 will rise to about 3.5bars. This pressure is then used to evacuate the treatment tank 29 after a decontamination cycle.

The treatment tank 29 is furthermore equipped with a low level sensor, a safety valve (for example calibrated at 7bar) and two temperature probes, in the low position for controlling the heating temperature and in position. high to confirm that the set temperature has been reached.

A duct 46 between the dome 45 of the treatment tank 29 and the storage tank 9 provided with a regulating valve 47 allows equalization of pressures between these two tanks, in particular during the filling of the treatment tank 29.

We will now describe an example of operation of the installation 1 described above assuming that the storage tank 9 was filled with a potentially pathogenic fluid at a level triggering a decontamination cycle and with reference to FIG. 5.

In a first step 100, the treatment tank 29 is filled with a potentially pathogenic fluid leaving a gaseous volume of expansion inside the treatment tank 29 at the dome 45. In the present example, the volume of treatment is only 81 so as to leave a gaseous free volume for expansion.

Then, according to a second step 102, the potentially pathogenic fluid is heated at a temperature of between 130 ° C. and 140 ° C., preferably at 135 ° C. for a period of time of between 1.5 min and 3 min, preferably for 2 min, allowing it to increase. the pressure in the treatment tank, for example here around 3.5bars. It is noted that the pressure in the treatment tank 29 is not regulated and is simply the result of the heating temperature, the heating time of the fluid in the treatment tank 29 and the volume of potentially pathogenic fluid admitted into the tank. which are chosen so that the pressure in the treatment tank 29 remains below the set pressure of the safety valve, the latter operating only in case of a problem, for example overheating.

Finally, according to a step 104, the fluid thus decontaminated is discharged using the pressure that has been established during heating.

Then, the decontaminated fluid is cooled during a step 106 in the heat exchanger 23. Thanks to the design of this installation, it produces practically no noise since there is no pump (s) to circulate the fluids. It is therefore clear that the decontamination unit allows effective decontamination and has increased reliability. In addition, its maintenance is easy and does not present particular difficulties.

Claims

Decontamination unit (19) for potentially pathogenic fluids comprising a treatment tank (29) and at least one heating element (31), characterized in that the treatment tank (29) comprises a flat bottom (33) and at least one heating element (31) fixed on the outer side (35) of the bottom plane (31) opposite to the inner side (37) intended to be in contact with the potentially pathogenic fluid, characterized in that the plane bottom (33) of the tank treatment (29) is inclined.

Decontamination unit according to claim 1, characterized in that the plane bottom (33) of the treatment tank (29) is inclined between 5% -10%, preferably 7%.

Decontamination unit according to one of Claims 1 to 2, characterized in that an outlet (43) of the treatment vessel (29) is provided at the inclined plane bottom (33) at the bottom of the slope ( 39).

Decontamination unit according to one of Claims 1 to 3, characterized in that the heating element (31) is a circular flat resistor.

Decontamination unit according to claim 4, characterized in that it comprises several, at least two concentric flat resistors (31a, 31B).

Decontamination unit according to any one of claims 1 to 5, characterized in that the treatment tank (29) is made of stainless steel, preferably of type 316L.

7. Decontamination facility (1) comprising

a sink (5) for collecting potentially pathogenic fluids,

- a storage tank (9) of the collected potentially pathogenic fluid fluidly connected to the sink,

- a decontamination unit (19) according to any one of claims 1 to 6, the inlet of which is fluidly connected to the outlet of the storage tank (9), and

- A heat exchanger (23) whose input is fluidly connected to the output of the decontamination unit (19).

8. Decontamination plant according to claim 7, characterized in that the sink (5) is arranged above the storage tank (9), in that the storage tank (9) is arranged above the storage tank (9). the decontamination unit (19), and in that the decontamination unit (19) is disposed above the heat exchanger (23) so that the circulation of potentially pathogenic fluids in the plant (1) is performed by gravity.

9. Installation according to claim 7 or 8, characterized in that it comprises a first control valve (21) arranged in a pipe (17) connecting the storage tank (9) to the decontamination unit (19) and a second control valve (25) disposed in a pipe (22) connecting the decontamination unit (19) to the heat exchanger (23).

Method for decontaminating potentially pathogenic fluids in a decontamination unit (19) according to one of claims 1 to 6, characterized in that - filling the treatment tank (29) with a potentially pathogenic fluid leaving a gaseous volume of expansion inside the treatment tank,

the potentially pathogenic fluid is heated at a temperature of between 130 ° C. and 140 ° C., preferably at 135 ° C. for a period of between 1.5 min and 3 min, preferably for 2 min, allowing the pressure to be increased in the treatment tank (29)

the fluid thus decontaminated is evacuated.